Jyothi, if you run the server from command line (not as a service) from terminal and then logged out from that terminal, the OpenERP will be shut down as well because it is attached to your terminal session.  The proper way is to set up a service daemon so that OpenERP will be running as a deamon instead of in your terminal session.  If you are in a hurry, just add & at the back of the command line, it will make the command line run at the background.  But it is not recommended for long term use.

i got the answer

If you're on Ubuntu, you can use an Upstart configuration file to autostart and manage your OpenERP instance.

Assuming you have a system user called "openerp", the following should work:

description "OpenERP 7.0" start on runlevel [2345] stop on runlevel [!2345] respawn exec su -s /bin/sh -c 'exec "$0" "$@"' openerp -- /opt/openerp/server/openerp-server -c /opt/openerp/config-server70.cfg --logfile=/opt/openerp/openerp-7.0.log $@

Adjust the config and log paths as you wish, and then save this in as /etc/init/openerp.conf.

Then, it will not only be automatically started on boot - as restarted if it dies, due to the respawn directive -, but you can also run restart openerp, stop openerp, etc instead of having to manually find the pid and kill it.

P.S.: The whole su -s /bin/sh -c exec ... is an Upstart "trick" to make OpenERP run as the "openerp" user, otherwise it would run as root!